Macroautophagy/autophagy is upregulated in pancreatic ductal adenocarcinoma (PDAC) and PDAC growth is reliant on autophagy. However, autophagy inhibitors as monotherapy have shown limited clinical ...efficacy. To identify targets that sensitize PDAC cells to autophagy inhibition, we performed a CRISPR-Cas9 genetic loss-of-function screen in cells treated with the lysosomal inhibitor chloroquine (CQ) and identified IGF1R as a sensitizer. IGF1R inhibition increases autophagic flux and sensitivity to CQ-mediated growth suppression both in vitro and in vivo. Importantly, sensitization is further enhanced with the concurrent inhibition of MAPK1/ERK2 (mitogen-activated protein kinase 1)-MAPK3/ERK1. IGF1R and MAPK/ERK inhibition converge on suppression of glycolysis. In summary, IGF1R and MAPK/ERK signaling promotes resistance to CQ/HCQ in PDAC, and their dual inhibition increases sensitivity to autophagy inhibitors.
Island Biogeography Reveals the Deep History of SIV Worobey, Michael; Telfer, Paul; Souquière, Sandrine ...
Science (American Association for the Advancement of Science),
09/2010, Letnik:
329, Številka:
5998
Journal Article
Recenzirano
Simian immunodeficiency virus (SIV) lineages have been identified that are endemic to Bioko Island. The time the island formed offers a geological time scale calibration point for dating the most ...recent common ancestor of SIV. The Bioko viruses cover the whole range of SIV genetic diversity, and each Bioko SIV clade is most closely related to viruses circulating in hosts of the same genus on the African mainland rather than to SIVs of other Bioko species. Our phylogeographic approach establishes that SIV is ancient and at least 32,000 years old. Our conservative calibration point and analyses of gene sequence saturation and dating bias suggest it may be much older.
The aggressive nature of pancreatic ductal adenocarcinoma (PDAC) mandates the development of improved therapies. As KRAS mutations are found in 95% of PDAC and are critical for tumor maintenance, one ...promising strategy involves exploiting KRAS-dependent metabolic perturbations. The macrometabolic process of autophagy is upregulated in KRAS-mutant PDAC, and PDAC growth is reliant on autophagy. However, inhibition of autophagy as monotherapy using the lysosomal inhibitor hydroxychloroquine (HCQ) has shown limited clinical efficacy. To identify strategies that can improve PDAC sensitivity to HCQ, we applied a CRISPR-Cas9 loss-of-function screen and found that a top sensitizer was the receptor tyrosine kinase (RTK) insulin-like growth factor 1 receptor (IGF1R). Additionally, reverse phase protein array pathway activation mapping profiled the signaling pathways altered by chloroquine (CQ) treatment. Activating phosphorylation of RTKs, including IGF1R, was a common compensatory increase in response to CQ. Inhibition of IGF1R increased autophagic flux and sensitivity to CQ-mediated growth suppression both in vitro and in vivo. Cotargeting both IGF1R and pathways that antagonize autophagy, such as ERK-MAPK axis, was strongly synergistic. IGF1R and ERK inhibition converged on suppression of glycolysis, leading to enhanced dependence on autophagy. Accordingly, concurrent inhibition of IGF1R, ERK, and autophagy induced cytotoxicity in PDAC cell lines and decreased viability in human PDAC organoids. In conclusion, targeting IGF1R together with ERK enhances the effectiveness of autophagy inhibitors in PDAC.
Compensatory upregulation of IGF1R and ERK-MAPK signaling limits the efficacy of autophagy inhibitors chloroquine and hydroxychloroquine, and their concurrent inhibition synergistically increases autophagy dependence and chloroquine sensitivity in pancreatic ductal adenocarcinoma.
Low-penetrance genetic variants have been increasingly recognized to influence the risk of tumor development. Risk variants for colorectal cancer (CRC) have been mapped to chromosome positions ...8q23.3, 8q24, 9p24.1, 10p14, 11q23, 14q22.2, 15q13, 16q22.1, 18q21, 19q13.1 and 20p12.3. In particular, the 8q24 single nucleotide polymorphism (SNP), rs6983267, has reproducibly been associated with the risk of developing CRC. As the CRC risk SNPs may also influence disease outcome, thus in this study, we evaluated whether they influence patient survival.
DNA samples from 583 CRC patients enrolled in the prospective, North Carolina Cancer Care Outcomes Research and Surveillance Consortium Study (NC CanCORS) were genotyped for 11 CRC susceptibility SNPs at 6 CRC risk loci. Relationships between genotypes and patient survival were examined using Cox regression analysis. In multivariate analysis, patients homozygous for the CRC risk allele of rs7013278 or rs7014346 (both at 8 q24) were only nominally significant for poorer overall survival compared to patients homozygous for the protective allele (hazard ratio = 2.20 and 1.96, respectively; P<0.05). None of these associations, however, remained statistically significant after correction for multiple testing. The other nine susceptibility SNPs tested were not significantly associated with survival.
We did not find evidence of association of CRC risk variants with patient survival.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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Introduction
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Characteristics
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The forkhead/winged‐helix protein transcription factor (FoxP3)
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Cytotoxic T lymphocyte–associated antigen 4 (CTLA‐4)
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Glucocorticoid‐induced TNFR Related ...Protein (GITR)
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L‐Selectin (CD62L)
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Chemokine (C‐C motif) Receptor 7 (CCR7)
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Alpha E integrin (CD103)
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Other cell markers with potential
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Manipulation of CD4+ CD25+ Tregs
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Induction and regulation of CD4+ CD25+ Tregs
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Interleukin‐2 (IL‐2)
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Interferon gamma (IFN‐γ)
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Transforming growth factor β1 (TGF‐β1)
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FoxP3
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Cytokines and drugs with potential
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Depletion of CD4+ CD25+ Tregs
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Role of CD4+ CD25+ FoxP3+ Tregs in disease
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Bacterial and fungal
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Parasitic infections
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Viral infections
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Autoimmunity and cancer
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Conclusions
CD4+ CD25+ T regulatory cells (Tregs) are classified as a subset of T cells whose role is the suppression and regulation of immune responses to self and non‐self. Since their discovery in the early 1970s, the role of CD4+ CD25+ Tregs in both autoimmune and infectious disease has continued to expand. This review exam‐ines the recent advances on the role CD4+ CD25+ Tregs may be playing in various diseases regarding pro‐gression or protection. In addition, advances made in the purification and manipulation of CD4+ CD25+ Tregs using new cell markers, techniques and antibodies are discussed. Ultimately, an overall understanding of the exact mechanism which CD4+ CD25+ Tregs implement during disease progression will enhance our ability to manipulate CD4+ CD25+ Tregs in a clinically beneficial manner.
Exposure of the skin to volatile organic chemicals (VOCs) can lead to irritation, inflammation and cytotoxicity. Since VOCs are used in industrial, commercial and military applications, concern is ...mounting with respect to VOC safe exposure limits. Although traditional toxicological assessment of VOCs has utilized animal models, the use of alternative in vitro models is becoming more widespread. We have previously developed a sealed exposure system that prevents chemical loss through evaporation and enables calculation of target cell chemical dose. The present study utilized this in vitro exposure method to assess
m-xylene-induced cytotoxicity and antioxidant status in dermal equivalents (dermal fibroblasts in a collagen matrix). At the end of a 1- or 4-h exposure, cytotoxicity was measured using the MTT assay and the EC
50 values determined were 1481±88 and 930±33, respectively. Decreases in cellular thiols and catalase activity were observed, which occurred in a time and dose-dependent manner. Treatment of dermal equivalents with the antioxidants
N-acetylcysteine (NAC) and catalase provided some protection against
m-xylene-induced cytotoxicity. When compared to
m-xylene exposures, treatment with either 1.0 or 5.0 mM NAC led to increases in the EC
50 values at 1 and 4 h. Increases in these EC
50 values ranged from 1.22- to 1.32-fold at 1 h and 1.27- to 1.54-fold at 4 h. Although treatment with catalase (1000 U/ml) led to a 1.35-fold increase in cell viability at 1 h, no significant differences were observed at either 1 or 4 h when compared to dermal equivalents exposed to
m-xylene alone. These results suggest that exposure to
m-xylene leads to a time- and dose-dependent decrease in cellular antioxidants and that cellular thiols may provide protection against the cytotoxic properties of
m-xylene.
p-Coumaroyl-CoA 3'-hydroxylase (C3'H) is a cytochrome P450-dependent monooxygenase that catalyzes the 3'-hydroxylation of p-coumaroyl shikimate and p-coumaroyl quinate. We used RNA interference to ...generate transgenic hybrid poplar suppressed in C3'H expression and analyzed them with respect to transcript abundance, cell wall structure and chemical composition, and soluble metabolite levels. RT-PCR expression profiles confirmed the down-regulation of C3'H in a number of lines, which generally correlated very well with reduced total cell wall lignin content. The most strongly repressed line was chosen for further analysis and compared with the wild-type trees. In-depth characterization revealed that along with the significant decrease in total lignin content, a significant shift in lignin monomer composition was observed, favoring the generation of p-hydroxyphenyl units at the expense of guaiacyl units while the proportion of syringyl moieties remained constant. Suppression of C3'H also resulted in the accumulation of substantial pools of 1-O-p-coumaroyl-β-D-glucoside and other phenylpropanoid glycosides, and p-coumaroyl shikimate, providing further insight into the role of C3'H in the lignin biosynthetic pathway. The data presented indicate that when down-regulated, C3'H becomes a rate-limiting step in lignin biosynthesis and further support the involvement of hydroxycinnamic acid shikimate esters in the lignin biosynthetic pathway.
The honey bee (Apis mellifera L.) contributes ∼$17 billion annually to the United States economy, primarily by pollinating major agricultural crops including almond, which is completely dependent on ...honey bee pollination for nut set. Almond growers face constant challenges to crop productivity owing to pests and pathogens, which are often controlled with a multitude of agrochemicals. For example, fungicides are often applied in combination with other products to control fungal pathogens during almond bloom. However, the effects of fungicides on honey bee health have been so far understudied. To assess the effects of some of the top fungicides used during the 2012 California almond bloom on honey bee forager mortality, we collected foragers from a local apiary and exposed them to fungicides (alone and in various combinations) at the label dose, or at doses ranging from 0.25 to 2 times the label dose rate. These fungicides were Iprodione 2SE Select, Pristine, and Quadris. We utilized a wind tunnel and atomizer set up with a wind speed of 2.9 m/s to simulate field-relevant exposure of honey bees to these agrochemicals during aerial application in almond fields. Groups of 40–50 foragers exposed to either untreated controls or fungicide-laden treatments were monitored daily over a 10-d period. Our results showed a significant decrease in forager survival resulting from exposure to simulated tank mixes of Iprodione 2SE Select, as well as synergistic detrimental effects of Iprodione 2SE Select in combination with Pristine and Quadris on forager survival.
Building on a successful 2019 survey of 153 km2 of Lake Huron bottomlands, the Ocean Exploration Trust and partners returned to Thunder Bay National Marine Sanctuary (TBNMS) in June 2021 for a 16-day ...mapping and five-day ROV exploration expedition. Concurrent with the 2021 E/V Nautilus expedition season, this two-phase, mobile mission brought together a variety of science and outreach partners to support the sanctuary mission to search for and document historically significant archaeological sites.
•SnapCard measured coverage precisely compared with industry standard image analysis software.•Kromekote is comparable to water-sensitive paper for coverage measurements.•Spray quality is an ...important factor influencing coverage.•SnapCard is a reliable tool for in-field image analysis of sprayed collectors.
Previous work sought to compare the results from imaging software for characterising droplet coverage, but none exists examining these five software programs: Droplet Scan®, Swath Kit®, Deposit Scan, Image J, and Drop Vision®-Ag. Additionally, a freely available smartphone application (App), SnapCard was developed to provide an extension tool for in-field analysis of spray collectors, but nothing has been published regarding its comparison to other imaging software systems. The present study was conducted to compare five existing imaging software types against the new App, SnapCard. Six nozzles producing different spray qualities were selected to spray a water+Brilliant Blue Dye solution over two artificial collector types (water sensitive paper and Kromekote®). Each collector was assessed for percent coverage using the five imaging systems and SnapCard. Objectives of this study were: 1. To establish a baseline dataset using the sprayed cards and five commonly used imaging systems, and compare the coverage results from each. 2. Use the baseline data from Objective 1 as a measurement of precision to judge the results from SnapCard. 3. Make an assessment of SnapCard against the other imaging software type data in the study.
Results showed that SnapCard has similar measured coverage means compared to other image analysis systems. For both collector types, SnapCard measured coverage within one standard deviation of the means across nozzle types. SnapCard is able to provide an immediate answer without expensive software or needing a laboratory to measure sprayed collector coverage with precise results, which further underscores its value. The other software types were not all similar for coverage, but the data followed the same trends for droplet size. Increasing the droplet size consistently decreased the coverage, across both collector types. Droplet Scan reported the highest coverage while Drop Vision-Ag and Swath Kit gave lower coverage values on water sensitive paper and Kromekote® collectors, respectively.
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